Data Sciences International (DSI) is developing an implantable battery powered flow meter-telemetry system for use in chronically instrumented animals. The transit time flow meter signal is telemetered at 2 MHz, while the simultaneously implanted telemetry system for blood pressure and ECG uses 455 kHz. This phase 2 application is buttressed by results of phase 1 that have accomplished specified goals regarding battery life, accuracy and reproducibility, freedom from interference and implantability. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE